From 13fd7a716c82f384f42f4dfb6c3e8a6b90f72054 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Lo=C3=AFc=20Hoguin?= Date: Fri, 2 Dec 2016 16:53:43 +0100 Subject: Update documentation --- .../2.0/manual/cowboy_req.body_length/index.html | 227 ++++++++++++++++ .../2.0/manual/cowboy_req.has_body/index.html | 218 +++++++++++++++ .../2.0/manual/cowboy_req.read_body/index.html | 281 +++++++++++++++++++ .../2.0/manual/cowboy_req.read_part/index.html | 300 +++++++++++++++++++++ .../manual/cowboy_req.read_part_body/index.html | 268 ++++++++++++++++++ .../cowboy_req.read_urlencoded_body/index.html | 264 ++++++++++++++++++ docs/en/cowboy/2.0/manual/cowboy_req/index.html | 4 +- docs/en/cowboy/2.0/manual/index.html | 30 +++ 8 files changed, 1590 insertions(+), 2 deletions(-) create mode 100644 docs/en/cowboy/2.0/manual/cowboy_req.body_length/index.html create mode 100644 docs/en/cowboy/2.0/manual/cowboy_req.has_body/index.html create mode 100644 docs/en/cowboy/2.0/manual/cowboy_req.read_body/index.html create mode 100644 docs/en/cowboy/2.0/manual/cowboy_req.read_part/index.html create mode 100644 docs/en/cowboy/2.0/manual/cowboy_req.read_part_body/index.html create mode 100644 docs/en/cowboy/2.0/manual/cowboy_req.read_urlencoded_body/index.html (limited to 'docs/en/cowboy/2.0/manual') diff --git a/docs/en/cowboy/2.0/manual/cowboy_req.body_length/index.html b/docs/en/cowboy/2.0/manual/cowboy_req.body_length/index.html new file mode 100644 index 00000000..0b200a7c --- /dev/null +++ b/docs/en/cowboy/2.0/manual/cowboy_req.body_length/index.html @@ -0,0 +1,227 @@ + + + + + + + + + + + + Nine Nines: cowboy_req:body_length(3) + + + + + + + + + + + + + + + + +

+ + + +

+ +

cowboy_req:body_length(3)

+ +

Name

cowboy_req:body_length - Body length

Description

body_length(Req :: cowboy_req:req()) -> undefined | non_neg_integer()

Return the length of the request body.

The length is not always known before reading the body. +In those cases Cowboy will return undefined. The body +length is available after the body has been fully read.

Arguments

+Req +: +
+The Req object. +
+

Return value

The length of the request body, or undefined if it is +not known.

Changelog

+
+2.0: Only the length is returned, it is no longer wrapped in a tuple. +
+
+
+1.0: Function introduced. +
+

Examples

Get the body length

Length = cowboy_req:body_length(Req).

cowboy_req:has_body(3)

+ +

Name

cowboy_req:has_body - Is there a request body?

Description

has_body(Req :: cowboy_req:req()) -> boolean()

Return whether the request has a body.

Arguments

+Req +: +
+The Req object. +
+

Return value

A boolean indicating whether the request has a body.

Changelog

+
+1.0: Function introduced. +
+

Examples

Ensure the request has a body

true = cowboy_req:has_body(Req).

cowboy_req:read_body(3)

+ +

Name

cowboy_req:read_body - Read the request body

Description

read_body(Req :: cowboy_req:req())
+    -> read_body(Req, #{})
+
+read_body(Req :: cowboy_req:req(), Opts)
+    -> {ok,   Data :: binary(), Req}
+     | {more, Data :: binary(), Req}
+
+Opts :: cowboy_req:read_body_opts()

Read the request body.

This function reads a chunk of the request body. A more tuple +is returned when more data remains to be read. Call the function +repeatedly until an ok tuple is returned to read the entire body.

An ok tuple with empty data is returned when the request has no body, +or when calling this function again after the body has already +been read. It is therefore safe to call this function directly. +Note that the body can only be read once.

This function reads the request body from the connection process. +The connection process is responsible for reading from the socket. +The exact behavior varies depending on the protocol.

The options therefore are only related to the communication +between the request process and the connection process.

Cowboy will automatically handle protocol details including +the expect header, chunked transfer-encoding and others.

Once the body has been read fully, Cowboy sets the content-length +header if it was not previously provided.

Arguments

+Req +: +
+The Req object. +
+
+Opts +: +
+A map of body reading options. +
+
The length option can be used to request smaller or bigger +chunks of data to be sent. It is a best effort approach, Cowboy +may send more data than configured on occasions. It defaults +to 8MB.
+
The period indicates how long the connection process will wait +before it provides us with the data it received. It defaults +to 15 seconds.
+
The connection process sends data to the request process when +either the length of data or the period of time is reached.
+
The timeout option is a safeguard in case the connection +process becomes unresponsive. The function will crash if no +message was received in that interval. The timeout should be +larger than the period. It defaults to the period + 1 second.
+

Return value

A more tuple is returned when there are more data to be read.

An ok tuple is returned when there are no more data to be read, +either because this is the last chunk of data, the body has already +been read, or there was no body to begin with.

The data is always returned as a binary.

The Req object returned in the tuple must be used for that point +onward. It contains a more up to date representation of the request. +For example it may have an added content-length header once the +body has been read.

Changelog

+
+2.0: Function introduced. Replaces body/1,2. +
+

Examples

Read the entire body

read_body(Req0, Acc) ->
+    case cowboy_req:read_body(Req0) of
+        {ok, Data, Req} -> {ok, << Acc/binary, Data/binary >>, Req};
+        {more, Data, Req} -> read_body(Req, << Acc/binary, Data/binary >>)
+    end.

Read the body in small chunks

cowboy_req:read_body(Req, #{length => 64000}).

cowboy_req:read_part(3)

+ +

Name

cowboy_req:read_part - Read the next multipart headers

Description

read_part(Req :: cowboy_req:req())
+    -> read_part(Req, #{})
+
+read_part(Req :: cowboy_req:req(), Opts)
+    -> {ok, Headers, Req} | {done, Req}
+
+Opts    :: cowboy_req:read_body_opts()
+Headers :: cow_multipart:headers()

Read the next part of a multipart body.

This function reads the request body and parses it as +multipart. Each parts of a multipart representation have +their own headers and body. This function parses and returns +headers. Examples of multipart media types are +multipart/form-data and multipart/byteranges.

Cowboy will skip any data remaining until the beginning of +the next part. This includes the preamble to the multipart +message but also the body of a previous part if it hasn’t +been read. Both are skipped automatically when calling this +function.

Cowboy will read the body before parsing in chunks of size +up to 64KB, with a period of 5 seconds. This is tailored for +reading part headers and might not be the most efficient for +skipping the previous part’s body.

The headers returned are MIME headers, NOT HTTP headers. +They can be parsed using the functions from the cow_multipart +module. In addition, the cow_multipart:form_data/1 function +can be used to quickly extract information from multipart/form-data +representations.

Once a part has been read, it can not be read again.

Once the body has been read, Cowboy sets the content-length +header if it was not previously provided.

Arguments

+Req +: +
+The Req object. +
+
+Opts +: +
+A map of body reading options. Please refer to +cowboy_req:read_body(3) +for details about each option. +
+
This function defaults the length to 64KB and the period +to 5 seconds.
+

Return value

An ok tuple is returned containing the next part’s headers +as a list of key/values.

A done tuple is returned if there are no more parts to read.

Changelog

+
+2.0: Function introduced. Replaces part/1,2. +
+

Examples

Read all parts

acc_multipart(Req0, Acc) ->
+    case cowboy_req:read_part(Req0) of
+        {ok, Headers, Req1} ->
+            {ok, Body, Req} = stream_body(Req1, <<>>),
+            acc_multipart(Req, [{Headers, Body}|Acc]);
+        {done, Req} ->
+            {lists:reverse(Acc), Req}
+    end.
+
+stream_body(Req0, Acc) ->
+    case cowboy_req:read_part_body(Req0) of
+        {more, Data, Req} ->
+            stream_body(Req, << Acc/binary, Data/binary >>);
+        {ok, Data, Req} ->
+            {ok, << Acc/binary, Data/binary >>, Req}
+    end.

Read all part headers, skipping bodies

skip_body_multipart(Req0, Acc) ->
+    case cowboy_req:read_part(Req0) of
+        {ok, Headers, Req} ->
+            skip_body_multipart(Req, [Headers|Acc]);
+        {done, Req} ->
+            {lists:reverse(Acc), Req}
+    end.

Read a part header in larger chunks

{ok, Headers, Req} = cowboy_req:read_part(Req0, #{length => 1000000}).

cowboy_req:read_part_body(3)

+ +

Name

cowboy_req:read_part_body - Read the current part’s body

Description

read_part_body(Req :: cowboy_req:req())
+    -> read_part_body(Req, #{})
+
+read_part_body(Req :: cowboy_req:req(), Opts)
+    -> {ok,   Data :: binary(), Req}
+     | {more, Data :: binary(), Req}
+
+Opts :: cowboy_req:read_body_opts()

Read the body of the current part of the multipart message.

This function reads the request body and parses it as +multipart. Each parts of a multipart representation have +their own headers and body. This function returns the +body of the current part. Examples of multipart media types +are multipart/form-data and multipart/byteranges.

This function reads a chunk of the part’s body. A more tuple +is returned when more data remains to be read. Call the function +repeatedly until an ok tuple is returned to read the entire body.

Once a part has been read, it can not be read again.

Once the body has been read, Cowboy sets the content-length +header if it was not previously provided.

Arguments

+Req +: +
+The Req object. +
+
+Opts +: +
+A map of body reading options. Please refer to +cowboy_req:read_body(3) +for details about each option. +
+
This function uses the same default options as the +cowboy_req:read_body(3) +function.
+

Return value

A more tuple is returned when there are more data to be read.

An ok tuple is returned when there are no more data to be read.

The data is always returned as a binary.

Changelog

+
+2.0: Function introduced. Replaces part_body/1,2. +
+

Examples

Read a full part’s body

stream_body(Req0, Acc) ->
+    case cowboy_req:read_part_body(Req0) of
+        {more, Data, Req} ->
+            stream_body(Req, << Acc/binary, Data/binary >>);
+        {ok, Data, Req} ->
+            {ok, << Acc/binary, Data/binary >>, Req}
+    end.

Ensure a part’s body is smaller than 64KB

{ok, Body, Req} = cowboy_req:read_part_body(Req0, #{length => 64000}).

cowboy_req:read_urlencoded_body(3)

+ +

Name

cowboy_req:read_urlencoded_body - Read and parse a urlencoded request body

Description

read_urlencoded_body(Req :: cowboy_req:req())
+    -> read_urlencoded_body(Req, #{})
+
+read_urlencoded_body(Req :: cowboy_req:req(), Opts)
+    -> {ok, Body, Req}
+
+Opts :: cowboy_req:read_body_opts()
+Body :: [{Key :: binary(), Value :: binary() | true}]

Read and parse a urlencoded request body.

This function reads the request body and parses it as +application/x-www-form-urlencoded. It returns a list +of key/values.

The urlencoded media type is used by Web browsers when +submitting HTML forms using the POST method.

Cowboy needs to read the full body before parsing. By default +it will read bodies of size up to 64KB. It is possible to +provide options to read larger bodies if required.

Cowboy will automatically handle protocol details including +the expect header, chunked transfer-encoding and others.

Once the body has been read, Cowboy sets the content-length +header if it was not previously provided.

This function can only be called once. Calling it again will +result in undefined behavior.

Arguments

+Req +: +
+The Req object. +
+
+Opts +: +
+A map of body reading options. Please refer to +cowboy_req:read_body(3) +for details about each option. +
+
This function defaults the length to 64KB and the period +to 5 seconds.
+

Return value

An ok tuple is returned containing a list of key/values found +in the body.

Changelog

+
+2.0: Function introduced. Replaces body_qs/1,2. +
+

Examples

Read a urlencoded body

{ok, Body, Req} = cowboy_req:read_urlencoded_body(Req0),
+{_, Lang} = lists:keyfind(<<"lang">>, 1, Body).

Allow large urlencoded bodies

{ok, Body, Req} = cowboy_req:read_urlencoded_body(Req0, #{length => 1000000}).

cowboy_req:body_length(3)

Name

Description

Arguments

Return value

Changelog

Examples

See also

+ Cowboy + 2.0 + Function Reference + +

Navigation

Version select

cowboy_req:has_body(3)

Name

Description

Arguments

Return value

Changelog

Examples

See also

+ Cowboy + 2.0 + Function Reference + +

Navigation

Version select

cowboy_req:read_body(3)

Name

Description

Arguments

Return value

Changelog

Examples

See also

+ Cowboy + 2.0 + Function Reference + +

Navigation

Version select

cowboy_req:read_part(3)

Name

Description

Arguments

Return value

Changelog

Examples

See also

+ Cowboy + 2.0 + Function Reference + +

Navigation

Version select

cowboy_req:read_part_body(3)

Name

Description

Arguments

Return value

Changelog

Examples

See also

+ Cowboy + 2.0 + Function Reference + +

Navigation

Version select

cowboy_req:read_urlencoded_body(3)

Name

Description

Arguments

Return value

Changelog

Examples

See also

+ Cowboy + 2.0 + Function Reference + +

Navigation

Version select